Thread-cutter for sewing-machines.



No. 726,318. PATBNTED APR. 2851903.. B. L. LYONS.

THREAD CUTTER FOR SEWING MACHINES.

APPLICATION FILED NOV. 14, 1901.

N0 MODEL.

0%0W. if if c nve nio r.- z. 2

rrnn Smarts nrnnr rricE.

ROBERT L. LYONS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO UNION BUTTON SENVING MACHINE COMPANY, OF BOSTON, MASSACHUSETTS.

THREAD' CUTTER FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Batent No. 726,318, dated April 28, 1903. Application filed November 14, 1901. Serial No. 82,233. (No model.)

To all whom it may concern.-

Be it known that 1, ROBERT L. LYoNs, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Thread-Cutting Attachments for Sewing-Machines, of which the following is a specification.

This invention relates to attachments for sewing-machines for sewing on buttons or performing an analogous operation in which the needle-thread requires to be broken and held in position for a succeeding operation for the purpose of saving time and labor.

The object of the invention is to provide a cutting and gripping attachment for severing and holding the needle-thread in connection with the Work-clamp for holding the work in position to be operated on by the stitching mechanism, the whole being self-contained and detachable, so as to be applied to existing machines.

Of the accompanying drawings, Figure 1 represents a plan view of a thread-cutting attachment constructed in accordance with my invention. Fig. 2 represents a plan View, partly in section, with the cutting and gripping jaws closed. Fig. 3v represents a front elevation. Fig. i represents a side elevation. Fig. 5 represents a detail side elevation showing the acting portions of the working members. Fig. 6 represents a similar View with the parts in a different position; Fig. 7 rep resents a sectional view of the gripping and cutting parts.

The same reference characters indicate the same parts in all the figures.

Referring to the drawings, 1 is a block or base having screw-holes 2 2 3, whereby it may be attached to a suitable part of the sewingmachine, and having clamping-jaws 4: 4 for holding down the fabric and gripping the button which is to be sewed onthe fabric,

said jaws and their operating mechanism being familiar features of prior machines.

5 are the gripping-jaws, pivoted to studs 6 6 on the upper side of the block 1, their outer or acting portions overlying the clampingjaws 4B 4. The acting portions of the jaws are normally held apart by a spring 7, connecting the heels of the jaws, and are adapted to be pressed together, so as to grip and cut the thread by means of a wedge-shaped camblock 8, mounted to slide on the upper side of the block 1 andguided by pins 9 10, occupying a slot 11 in said block. Motion is imparted to the cam-block 8 by a suitable part of the sewing-machine connecting with a stud 12 on the side of said block. The jaw 5 is provided with a solid gripping portion 13, coacting with a yielding gripping-block, 14L on the jaw 50 in gripping the thread. Said block is provided with two guide-studs 15 15, passing through holes in the jaw 50 and provided with heads 16 to limit the outward motion of the studs, which outward motion is yieldingly imparted by springs-l7 17, surrounding the studs. The under side of the jaw '50 is provided with a cutting-blade 18, adapted to underlap the jaw 5 when the jaws are brought together and to cooperate with the lower edge of said jaw 5, facing the jaw 50, in exerting a shearing or cutting action on the thread.

-By the action of the mechanisms controlling the motion of the block 1 and controlling the motion of the cam-block 8 and the mechanism controlling the needle 19 the jaws 5 50 are broughttogether. when the needle is up and the block 8 is advanced to bring the acting portions of the jaws 5 50 into the path of the needle, and the gripping-block 14 on jaw 50 is pushed back by the gripping portion 13 of jaw 5, so as to grip the thread and cause it to pass over the cutting edge of the cutter 15, whereby the thread is severed. The action of the controlling mechanism then retracts. the block-1, while the jaws 5 50 still grip the thread, and the starting thread 20 is thereby held to the rear of the needle ready for a new operation, as shown in Fig. 5.

I claim An attachment for sewing-machines comprising a base or support, a pair of workcla'mping jaws thereon, and a pair of threadengaging jaws pivoted to said support in a normally fixed relation to the work-clamping jaws and having coacting thread gripping and severing portions movable into and out of thread-engaging relation by the pivotal movement of said jaws.

In testimony whereof I have aflixed my signature in presence of two witnesses.

ROBERT L. LYONS.

Witnesses:

GEORGE Pnzznr'rr, R. M. PIERSON.

Ice 

